Storage stable fatty alcohol sulfates and method of manufacture



United States Patent Ofiice 3,305,577 STORAGE STABLE FATTY ALCOHOL SULFATES AND METHOD OF MANUFACTURE Karl Goldann, Dusseldorf, and Werner Stein, Dusseldorf- Holthausen, Germany, assignors to Henkel & Cie G.m.b.H., Dusseldorf-Holthausen, Germany, a corporation of Germany No Drawing. Filed Aug. 1, 1963, Ser. No. 299,200 Claims priority, application Germany, Aug. 16, 1962, H 46,653 5 Claims. (Cl. 260-459) This invention relates to the manufacture of storage stable fatty alcohol sulfate-containing products and particularly to a process of manufacturing substantially odorfree alcohol sulfates and products containing fatty alcohol sulfates.

The fatty alcohol sulfates are characterized by their tendency to undergo certain decomposition reactions whereby certain reaction products are formed, a considerable portion of which are impurities constituted as odoriferous bodies which impart an odor to and reduce the marketability and the utility for most purposes of the sulfonated fatty alcohols. In the case of sulfates of unsaturated fatty alcohols, the odor which is produced is so considerable and so unpleasant that the use of these products for those applications where the presence of any odor is most undesirable is made impossible. In the case of the more highly unsaturated sulfated products, this phenomenon is so pronounced that these products have not been suitable for any purpose. This characteristic has proven particularly unpleasant in connection with detergents prepared with fatty alcohol sulfates and which are widely sold for a variety of uses in which such odors are most undesirable. The odor develops only after the detergents have been stored for a period of time, is at first not pungent but peculiar, and which'unfortunately can be transferred to the materials or objects subjected to cleaning treatment with the detergent.

In the household market for laundering, dish washing, and the like, acceptability of the detergent in competition with natural soap products is enhanced by freedom from such unpleasant odors. The consumer has come to associate with the concept of purity a freedom from unpleasant odors. In the cosmetic field, shampoos containing sulfated products, merchandized either as clear liquids, opaque liquids, creams or solid products require substantial freedom from unpleasant odor contaminants for sales appeal. In the medical field and pharmaceutical field where such detergents are obtaining wide favor, purity, i.e., absence of odor as well as in the composition is an important attribute.

Prior efforts to solve the problem of the lack of stabilizing of sulfated fatty alcohols have not been successful. It has not been possible so far to completely prevent odor formation following the sulfonation processes. Adequate extraction of the odor-forming bodies from the detergent by the use of solvents is clearly not economical or really effective because of the continuing formation of the odorimparting bodies. Extraction by adsorption encounters the problem of extraction of the detergent itself and of inadequate removal of the odor-forming bodies for the reasons just set out above. Thus prior to the invention there has been no method available to successfully remove odorimparting bodies from detergent substances of the sulfate type in an economical or practical manner.

In accordance with the invention, it has now been found that phenols having a valency of two or more, and/or secondary aromatic amines of the general formula R NH-R in which R and R represents aromatic radicals which may be substituted as for instance by radicals containing amino groups can be employed to 3,305,577 Patented Feb. 21, 1967 stabilize fatty alcohol sulfates against the formation of decomposition products and therewith the formation of odors. The fatty alcohol sulfates suitable for such treatment can be in the form of high percentage fatty alcohol sulfate products or detergents in which the fatty alcohol sulfate is present in an amount of at least 2%. The product resulting from the treatment is a substantially odorfree fatty alcohol sulfate with a marked absence of the odor contamination which would characterize the same fatty alcohol sulfate product or detergent made without the addition of a polyvalent phenol and/or amine.

The stabilizers in accordance with the invention are effective even in small amounts. The minimum amount to be used depends of course on the choice of a fatty alcohol sulfate to be stabilized. In general, amounts of between 0.01% to 0.3% referred to the amount of fatty alcohol sulfate and, preferably, 0.05 to 0.2% are used for producing stabilization. In special cases, however, larger amounts may be necessary. However, on the average, the addition of a maximum of 0.3% referred to, the fatty alcohol sulfate present will produce satisfactory results.

The following are instances of secondary aromatic amines which are suitable for use as stabilizers according to the invention, diphenylamines, the substitution products thereof, phenylnaphthylamine, dinaphthylamine, pyridylphenylamine, aromatically substituted phenyldiamines, such for example di-B-naphthyl-p-phenylenediamine.

The following are instances of polyvalent phenols which may be used in accordance with the invention, hydroquinone, dioxydiphenyl, dioxynaphthalene.

Fatty alcohol sulfates which can be stabilized by treatment with an amine and/or phenol in accordance with the invention are derived from fatty alcohols usually having from 8 to 20 carbon atoms are usually obtained by reduction of commercial fatty or fixed oils of animal, vegetable, fish, or other marine origin, as for instance, coconut oil, palm oil, tallow, stearin, castor oil, wool fat, lard oil, linseed oil, etc. Typical examples are the sulfation products of lauryl, alcohol, cetyl alcohol, stearyl alcohol, ricinoleyl alcohols, linoleyl alcohol and oleyl alcohol. Similar products are obtained by the sulfation of socalled synthetic alcohols such as those prepared by catalytically combining a mixture of hydrogen and carbon monoxide with an olefinic hydrocarbon by oxidation of hydrocarbons, by hydration of olefins, etc. Further sulfation products to form detergents as for example obtained by treating a high molecular weight compound with strong sulfuric acid or its equivalent in the art may be treated to remove the odor-imparting bodies according to this invention.

In the practice of the invention the additives are added to and worked into the fatty alcohol sulfates or detergents containing fatty alcohol sulfates by the conventional methods.

Thus, for example, they can be incorporated into the mixture prior to spray drying or after the fatty alcohol sulfate material is already in powdered form or, alternatively, they can be admixed with the finished powder preparation.

The following are given as illustrative of the invention, but it is not intended that the same be considered in any way as limiting the scope thereof.

Example 1 The stabilizing effect on sulfated fatty alcohols and on detergents containing fatty alcohol sulfates of the additives of the invention was evaluated. The fatty alcohols were prepared by reduction of the fatty acids .set out below. These fatty acids were sulfated with aminosulfonic acid, converted into sodium salts and spray dried in a 3: K-rause tower. The effect of the additive of the invention was evaluated on the basis of the olfactory impression produced by the fatty alcohol sulfates or detergent sambefore spray drying. The following table shows the ratings of the olfactory impression with respect to samples over a period of from 6 to 140 hours.

ples containing the same using gram quantities of each, TABLE II the samples being placed in powder bottles having a 5 capacity of 500 cc. To accelerate the odor forming proc- Hours 6 3O 54 78 102 12s 1 140 ess and namely to shorten the test time, the flasks were sealed with glass stoppers and stored at 90 C. Six ratmtmgsqfl 1 H 2 I 2 l 2 I 2 ings were established for evaluating the olfactory impression, 1 representing the best rating and 6 the least The detergent sample containing no stabilizer had an satlsfactor'y; Between F ratmgs and the (Pdor of unpleasant smell even after 6 hours, which intensified as deCOmPOSWOWIS manlfested' 4 was glven to time Went on. After 30 hours, an extremely unpleasant products in which the decomposition odor was barely perodor of decomposition was perceptib1e ceptible. After each odor test, which was conducted at l 3 intervals of 24 hours, the air in the flasks was replaced, Emmi 6 since even the slightest traces of decomposition products U d h di i d ib d i Exafnplg 1 a d give rise to a Strong Odof- In this manner it Was Possible tergent having the following composition was evaluated: 213 52? 53:? between mclplent continuing develop- 7% alkylsulfate of saturated fatty alcohols (C -C Sodium oleyl alcohol sulfate derived from sperm fatty 3 letrqprogylenebenzenesulfonate 2.5%: boric acid buffer acid, in powder form (A), the llqllld components of 60% sodium Sulfate cottonseed oil fatty acid separated at 20 C. (B), and technical oleic acid (C), having the following composi- 0.05% 4,4'-d1oxyd1phenyl was added to the mix prior to tions, were evaluated: spray drying. The olfactory impression reported for the detergent sample over a course of 140 hours is set out in gaming l'attylrfilcogol s ira e fl 43. 4 .1 41.; Table III by the Tatlngs glven therewercen unsu ate at o 0. .8 1. Percent water 3. 8.8 2. 7 2.9 TABLE III li ercentts allalinity lcfaltculated as NZLzO 55.213 52 erccn so tum su a e a. Iodine number in the cleavage alcohol 622 83.3 74.0 20 Hours "t 6 t t 78 t 102 t 126 i no By Iodine number in the cleavage alcohol is meant the iodine Ratings"" 1 t 2 3 t 3 t 3-4 t 3-4 nuliinlaer of the fatty alcohol formed by saponification of the fatty alcohol W A e A detergent sample of the above composition con- In Table I which follows are ShOWn th averages f tW taining no stabilizing additive developed an unpleasant, experimental series. 0.1% of an inhibitor in accordance pungent odor after only 30 hours. with the invention was added to the samples before spray What is claimed is: drying, and the odor changes after 24, 70 and 144 hours 1. A substantially odor-free, storage stable product were determined. The stabilizers used in the tests are comprising a sodium salt of a sulfated fatty alcohol conshown in the first three examples of Table 1. Examples taining 8-20 carbon atoms in admixture with 0.05 to 0.2% 5 to 9 contain the results of comparative tests using known referred to said sodium salt of a sulfated fatty alcohol of oxidation inhibitors, which are without the scope of the at least one member selected from the group consisting invention. of hydroquinone, dioxydiphenyl, dioxynaphthalene and TABLE I Product A B o Inhibitor Time, hrs.

Pheuyl-fl-uaphthylamine 1-2 2 2 2 2-3 3-4 2 2-3 2 Di-fiuaphthyl-p-pheuyleu 2 2 1-2 2 2 2 1 1-2 2 4,4-dioxydipheuyl 2 2-3 2-3 3 4 4 2-3 3 3-4 None 3-4 4 5-6 4 4 4-5 3-4 4 4 Ethyleuediaminetetraacctic acid. 3 4-5 5-6 3-4 4 3-4 3 4 4-5 l\Ionosodium-iron (II)- hydroxyethyl- 3 4 4 3-4 4 4 3-4 4 4 etlrvleue-diamiuc-t riacetic acid. 7 Bntyl"ydroxyauisole s-3 2-3 4-5 3-4 4 4-5 2 4 5-6 5 P ops slallate 4 3-4 5-5 4 4 4 4 4-5 5-6 9". Di-tert.-butyl-p-cresol i. 3-4 3-4 5 4 4 4 3 3-4 5-6 Example 2 secondary amines having the formula R NHR where- A detergent, having the following composition: m each of R1 and R2 13 a .membfir Selected from.the group consisting of phenyl, pyridyl, and ,B-naphthylamrno- 6% coconut fatty alcohol sulfate p-phenylene. 24% tetfaprQpylenebenzenesulfonate 2. A substantially odor-free, storage stable product ac- 3% bOTlC 391d bllficel" cording to claim 1 wherein said group member is phenyl- 64% sodium sulfate was tested under the conditions described in Example 1. A spray-dried detergent sample containing no stabilizing additive was used, for comparison with another detergent sample to which 0.1% 4,4'-dioxydiphenyl had been added fl-naphthylamine.

3. A substantially odor-free, storage stable product according to claim 1 wherein said group member is di-[inaphthyl-p-phenylenediamine.

4. A substantially odor-free, storage stable product ac,-

cording to claim 1 wherein said dioxydiphenyl.

5. A process of preparing a storage stable, substantially odor-free sulfated fatty alcohol containing product which comprises adding to a sodium salt of a sulfated fatty alcohol containing 8-20 carbon atom, 0.05 to 0.2% referred to said sodium salt of a sulfated fatty alcohol of at least one member selected from the group Consisting of hydroquinone, dioxydiphenyl, dioxynaphthalene and secondary amines having the formula R NHR wherein each of R and R is a member selected from the group consisting of phenyl, pyridyl, and p-naphthylamino-pphenylene.

group member is 4,4-

References Cited by the Examiner UNITED STATES PATENTS Long 260459 Bertsch 260459 Mitchell et al. 260-308 Callahan 252l36 Schwartz 252-136 

1. A SUBSTANTIALLY ODOR-FREE, STORAGE STABLE PRODUCT COMPRISING A SODIUM SALT OF A SULFATED FATTY ALCOHOL CONTAINING 8-20 CARBON ATOMS IN ADMIXTURE WITH 0.05 TO 0.2% REFERRED TO SAID SODIUM SALT OF A SULFATED FATTY ALCOHOL OF AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF HYDROQUINONE, DIOXYDIPHENYL, DIOXYNAPHTHALENE AND SECONDARY AMINES HAVING THE FORMULA R1-NH-R2 WHEREIN EACH OF THE R1 AND R2 IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF PHENYL, PYRIDYL, AND B-NAPHTHYLAMINOP-PHENYLENE. 